88Irocker

Hey guys - my 88 305 TPI failed the NJ emissions yesterday. It passed last time when they used to run it on the dyno. Now that they just test it at standstill, it failed, go figure! My HC's were about 350 at idle (should be 250) and the CO was a little over. NOx were fine. It only failed at idle speed. They do a "fast idle" test - sounded like they held it at about 2,000 RPM, and it passed that. My question is, what affects the HC's and what can I do to clean it up?

The car is mostly stock with the following changes:

180* stat
210/185* fan switch.
NGK plugs - 1 stage colder
I think timing is set around 8 or 9 degrees advanced.
I run it on 89 octane fuel b/c it pings a little at heavy load (the EGR valve and solenoid are newer parts - b/c it failed the NOx 4 years ago!)
Car got new fuel injectors a few years ago.
Car has 93K miles.

Should I put stock heat range plugs back in?
How does the ignition timing affect HC's?
If I run 87 octane, would that burn cleaner?
Do any of those "additives" in Pep Boys work on the HC's and CO?
Since it runs cleaner at higher RPM, can I step up the idle speed to about 1,000 RPM with that little screw on the side of the throttle body? Or will the ECU pull it back?

Thanks for any ideas.

Dave

cars3

The only advice I can give you is keep your car stock in NJ. I lived there for 2 1/2 years while I was in the Air Force stationed at McGuire Air Force Base. Everybody I knew that made small mods to their cars were failing. I never had to worry about it because I had Michigan plates and was not required at the time in 1997 to switch to NJ plates because I lived on the base. Good luck!!!!!!!!!!!!!

mikey dragster

Holy 22 years old, Ever thought of updating ? . . .

Mike